Mr Ngom was arrested because he did not turn up for questioning by prosecutors looking into claims that senior members of Mr Wade's government used their positions for personal gain, according to the BBC.

The former minister had previously been criticised in March after police shot and killed at least six opposition supporters demonstrating against Mr Wade's re-election bid.

Several former officials have been questioned by a special court - notably Mr Wade's son, Karim, who many Senegalese believed was being groomed as his father's successor.

The former president himself has not been left untouched and several cars that were bought in his name have been confiscated in a dispute over their lawful owner, Mr Wade or the state.

The opposition says the corruption investigations initiated by President Sall are "biased".

A former close associate of Mr Wade, Mr Sall beat him in the second round after winning the support of other opposition parties.

He is Senegal's fourth president since the west African nation gained independence from France in 1960.